The International Criminal Court has told the BBC that it will “analyse materials” it has received about the violence which hit Nigeria last month following protests against police brutality.

The ICC chief prosecutor’s office said that contrary to an earlier report, it has not already opened a “formal preliminary examination” into the unrest.

For weeks crowds of peaceful protesters gathered in streets in major cities of Nigeria to demonstrate against police brutality.

The protests were held under the #EndSars banner, a reference to demands for the disbandment of the notorious Special Anti-Robbery Squad, whose officers were repeatedly accused of criminal activity ranging from extortion to extra-judicial killings.

It led to a crackdown, with security forces and armed thugs accused of killing protesters.

Some 51 civilians, 11 police officers and seven soldiers were killed in the unrest, according to Nigerian President Muhammadu Buhari.

Rights group Amnesty International said security forces opened fire on protesters at the Lekki toll gate in the commercial hub of Lagos, killing 10 people there.

The military and police rejected Amnesty’s allegation.

Some civil rights have been pushing for the ICC to investigate the violence.